Add constants to __all__, update function to return a bound queue on success.
Add constants to __all__, update function to return a bound queue on
success.

StackStorm/st2,StackStorm/st2,nzlosh/st2,Plexxi/st2,Plexxi/st2,StackStorm/st2,Plexxi/st2,StackStorm/st2,nzlosh/st2,Plexxi/st2,nzlosh/st2,nzlosh/st2